vs2008 中auto_ptr

最新推荐文章于 2024-03-20 22:11:49 发布

「已注销」

最新推荐文章于 2024-03-20 22:11:49 发布

阅读量558

点赞数

分类专栏： c++

c++ 专栏收录该内容

0 篇文章

订阅专栏

本文详细介绍了模板类auto_ptr的功能、构造方法、赋值操作、析构方法及使用注意事项，旨在帮助开发者理解并有效利用这一类在智能指针中的应用。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

		// TEMPLATE CLASS auto_ptr
template<class _Ty>
	class auto_ptr;

template<class _Ty>
	struct auto_ptr_ref
		{	// proxy reference for auto_ptr copying
	explicit auto_ptr_ref(_Ty *_Right)
		: _Ref(_Right)
		{	// construct from generic pointer to auto_ptr ptr
		}

	_Ty *_Ref;	// generic pointer to auto_ptr ptr
	};

template<class _Ty>
	class auto_ptr
		{	// wrap an object pointer to ensure destruction
public:
	typedef _Ty element_type;

	explicit auto_ptr(_Ty *_Ptr = 0) _THROW0()
		: _Myptr(_Ptr)
		{	// construct from object pointer
		}

	auto_ptr(auto_ptr<_Ty>& _Right) _THROW0()
		: _Myptr(_Right.release())
		{	// construct by assuming pointer from _Right auto_ptr
		}

	auto_ptr(auto_ptr_ref<_Ty> _Right) _THROW0()
		{	// construct by assuming pointer from _Right auto_ptr_ref
		_Ty *_Ptr = _Right._Ref;
		_Right._Ref = 0;	// release old
		_Myptr = _Ptr;	// reset this
		}

	template<class _Other>
		operator auto_ptr<_Other>() _THROW0()
		{	// convert to compatible auto_ptr
		return (auto_ptr<_Other>(*this));
		}

	template<class _Other>
		operator auto_ptr_ref<_Other>() _THROW0()
		{	// convert to compatible auto_ptr_ref
		_Other *_Cvtptr = _Myptr;	// test implicit conversion
		auto_ptr_ref<_Other> _Ans(_Cvtptr);
		_Myptr = 0;	// pass ownership to auto_ptr_ref
		return (_Ans);
		}


	template<class _Other>
		auto_ptr<_Ty>& operator=(auto_ptr<_Other>& _Right) _THROW0()
		{	// assign compatible _Right (assume pointer)
		reset(_Right.release());
		return (*this);
		}

	template<class _Other>
		auto_ptr(auto_ptr<_Other>& _Right) _THROW0()
		: _Myptr(_Right.release())
		{	// construct by assuming pointer from _Right
		}

	auto_ptr<_Ty>& operator=(auto_ptr<_Ty>& _Right) _THROW0()
		{	// assign compatible _Right (assume pointer)
		reset(_Right.release());
		return (*this);
		}

	auto_ptr<_Ty>& operator=(auto_ptr_ref<_Ty> _Right) _THROW0()
		{	// assign compatible _Right._Ref (assume pointer)
		_Ty *_Ptr = _Right._Ref;
		_Right._Ref = 0;	// release old
		reset(_Ptr);	// set new
		return (*this);
		}

	~auto_ptr()
		{	// destroy the object
		if (_Myptr != 0)
			delete _Myptr;
		}

	_Ty& operator*() const _THROW0()
		{	// return designated value

 #if _HAS_ITERATOR_DEBUGGING
		if (_Myptr == 0)
			_DEBUG_ERROR("auto_ptr not dereferencable");
 #endif /* _HAS_ITERATOR_DEBUGGING */

		__analysis_assume(_Myptr);

		return (*get());
		}

	_Ty *operator->() const _THROW0()
		{	// return pointer to class object

 #if _HAS_ITERATOR_DEBUGGING
		if (_Myptr == 0)
			_DEBUG_ERROR("auto_ptr not dereferencable");
 #endif /* _HAS_ITERATOR_DEBUGGING */

		return (get());
		}

	_Ty *get() const _THROW0()
		{	// return wrapped pointer
		return (_Myptr);
		}

	_Ty *release() _THROW0()
		{	// return wrapped pointer and give up ownership
		_Ty *_Tmp = _Myptr;
		_Myptr = 0;
		return (_Tmp);
		}

	void reset(_Ty* _Ptr = 0)
		{	// destroy designated object and store new pointer
		if (_Ptr != _Myptr && _Myptr != 0)
			delete _Myptr;
		_Myptr = _Ptr;
		}

private:
	_Ty *_Myptr;	// the wrapped object pointer
	};